Unlike some shows that generally keep similar pace with real life—where a season is a year—Breaking Bad doesn't seem to. Currently (part-way though season 5), the characters were remarking that it had been a year since Walt's cancer diagnosis, though I forgot when that was relative to the premiere (if it happened 'then', or in a flashback).

Walt's 50th birthday was in the pilot (in the "present" of that episode). That recent episode had his 51st.
–
user209Aug 15 '12 at 21:38

@Keen Got it; but how do each of the seasons compare time-wise?
–
Nick TAug 15 '12 at 22:04

2

An episode-by-episode timeline for the first three seasons can be read here.
–
Oliver_CAug 20 '12 at 8:41

In short, assuming this last bit of the show starts around where the opening of the season hinted at, what we've seen so far has taken place over the course of 2 years from the Pilot.
–
TylerShadsDec 3 '12 at 13:32

In the pilot, we see Walt celebrate his 50th birthday (this is where we see the "bacon spelling out his age" thing for the first time). In S5E4 Fifty-One, we see him celebrate his 51st birthday. In S5E1, we see a flashforward where Walt is celebrating his 52nd birthday alone in a diner. In the last episode, we see the flashforward resume, so the show ends around Walt's 52nd birthday. Beyond that, I'm not sure how long each season was, but those are some anchor points for how much time has passed during the show.

Was the intro to the season 5 premiere actually a year on? IIRC he was using some fake ID which would probably have a different DOB.
–
Nick TAug 19 '12 at 6:21

5

@NickT There's little reason for him to pretend its his 52nd birthday using the same ritual that his family uses, I think. By including the bacon numbers, the writers were showing us that in a year, things will go bad.
–
user209Aug 19 '12 at 15:00

@NickT - I concur that it would be improbable to have Walt change his date of birth just for a fake ID. Hence, the entire series will encompass roughly 2 years between Walts's 50th and 52nd birthdays; the diner scene this season's premiere shows forshadows a showdown right after his birthday.
–
wbogaczJul 27 '13 at 20:22

I'm pretty certain that season 2 episode 12 was set in March 2009 as Jane was born in April 1982 and her dad said she would be turning 27 the following month. Working back using the timeline posted elsewhere the series began in October 2008 and this was when Walt turned 50. What all that means is that each season has only covered about three months.